Luminescent tube



A. S. FORD LUMINESCENT TUBE Filed May 3l, 1928 July 23, 1935.

' July\23, 1935. A. s.. FORD 2,009,375

LUMINESCENT TUBE Filed May s1, 192e 5 sheets-sheet 2 INVENTOR July 23, 1935. A. s. FORD 2,009,375

LUMINES GENT TvUB E 'Filed May 31,. 1923 5 shets-sheet s INVENTOR July 23, 1935. A s. FORD 2,009,375

LUMINESGENT TUBE Filed May s1, 1928 5 sheets-sheet 4 July 23, 1935. A. s. CRD 2,009,375

LUMINESCENT TUBE Filed May 31, 1928 5 Sheets-Sheet 5 llllllr Patented July 23, 1935 UNiTso STATES PATENT ogm@ LUMINESCENT TUBE Arthur Stephen Ford, Philmont, N. Y., assigner to General Electric Vapor Lamp Co., Hoboken,

N. J., a corporation of New Jersey Application May 31, 1928, Serial No. 281,989 1 Claim. (Cl. 176-422) This invention relates to illuminating tubes of These baille plates as shown in Fig. 1 are or the neon type, and I will describe it with refsuch dimensions that they can be mounted on erence to the accompanying drawings: the central support 3 and inserted in the lamp Fig. 1 shows a sectional view of one form of my container through the opening at the neck of 5 improved lamp in which an outer container 1 the container before it is exhausted and sealed 5 preferably of glass is exhausted of air and filled but these baille plates may be of greater 'dimenwith neon or other suitable gas after which the sions if desired and the outer container .may be glass container is hermetically sealed at its base 2 blown or fashioned in two parts, that is, a lower by means familiar to those skilled in the art. The cup A in which the central rod maybe disposed container is provided with a central rod or supand the lead in wires and electrodes mounted and 10 port 3, preferably a glass tube, and this rod or a second upper dome shaped cover B may be then tube is provided with baille plates 4 and 5 at the superposed. Both this lower cup and upper dome lower and upper extremity respectively to serve may be provided with a turned lip or rim at the a purpose which will be described later. point of juncture and these rims or lips can be This central rod or tube also serves as a supcemented, melted, or welded together in any suitl5 port for the two electrodes 6 and 1 which are able or convenient mannerin which case the joint disposed as shown in relation to the bafile plates will be established at the point Ill as shown in 4 and 5 and which can be of any suitable ma- Fig. 1 or at any other convenient location. terial or shape. Lead in wires 8 and 9 passing Fig. 2 shows a modified form of one of my through the base of the container serve to convey lamps in which the use of baille plates is omitted, 20 the electric current to the two electrodes 6 and 1, the path of the exciting current through the gas the former being'preferably disposed around the being controlled by the interposition of a second central rod under the baille plate 4 andthe secinternal'container Il which supports the central ond electrode 'I being disposed at the top of the rod 3 and the electrodes 6 and 1. The electrode central rod or tube and above the baille plate 6 at the base is shown in ring form "shape, the 25 5, the lead in wire for the uppery electrode being gas chamber proper being the area between the carried up through the center of the glass tube internal container Il and the outer casing I.y 3 as shown. The baille plates 4 and. 5 can be of When the electrodes of such a lamp are excited glass and integral with the rod or support 3 orcan the luminous gas is conned to the said outside be made' of any other suitable material such as area lying under the outer case and the luminousv 30 sheet mica and separably attached to the central area is conned to such gas as is contained thererod. in. 'Ihe internal chamber Il may be exhausted When the electrodes of such a gas lled lamp of air and sealed from the luminous gas or may are excited by a suitable current, the current lbe exhausted of air and filled-With the luminous passes to and from the electrodes through the gas gas which is provided with means of access to 35 with which the lamp is lled exciting the particles the yexcited area through apertures I2 or the of such gas into luminosity. In the absence of internal chamber may be filled with air and herthe baffle plates 4 and 5 the current would take metically sealed from the gas area proper. y the shortest path through such gas and would Fig. 3 shows yet another form of lamp designed result in a luminous column of gas around the to control the area of the luminous gas in which 40 central rod but at some distance from the outer the baille plates as shown in Fig. l are dispensed wall of the glass container. The presence of the lwith and an internal chamber Il is employed to baille plates prevents this as the current is decontrol and secure a brush like discharge through nected laterally and away from the central rod the luminous gas from one electrode to the other.

and establishes a path adjacent to the inner sur- The internal chamber I I in this form of lamp 45 face of the lamp container as shown by the is blown or fashioned with Vertical depressions arrows in the drawings which indicate the path extending from top to bottom and this internal taken by the exciting current from the upper elecchamber is so constructed as to nest snugly withtrode to the lower electrode. in the outer casing I. The internal chamber is This results in greater diameter to the mass of suitably mounted and sealed in the outer case as 50 glowing gas with greater accompanying illuminashown, and provided with electrodes 6 and 1 contion and militates against overheating the elecnected by lead in wires 8 and 9. The gas area trodes and the central lead in wire as .well as preproper is provided by the vertical spaces left in venting conductionl losses through the glass centhe vertical depressions fashioned on the surface 5 5 tral tube to the said lead in wire. of the internal chamber and the electric current passing between -the electrodes 6 and I has to pass through the gas in such vertical depressions exciting it to luminescence.

The internal chamber can be air lled, gas filled, or exhausted of air and gas as may be desired.

I'he construction of this form of lamp will be more clearly understood by reference to Fig. 4 which represents a top view of the lamp on a line 4 4 as marked in Fig. 3; II is the internal chamber which fits snugly in'the outer case I. Vertical depressions I3 are radially disposed around the outer skin of the internal chamber I I, these depressions extending from the base I3.' (Fig. 3) to the top of said internal chamber I4 (Fig. 3). vWhile the drawings show these gas filled depressions which control the path of the luminous gas as vertical, I do not wish to confine myself to vertical depressions only, as it is obvious that they may be arranged spirally around the outer skin of the internal chamber I I or they may be given any other form without departing from the essential principle of this part of my invention which is to provide a definite restricted path for the luminous gas as near to the inside skin of the outside container as possible.

Similarly while the internal chamber II is described as made of clear glass, it may be made of opal or colored glass, may be silvered inside or out, or decorated in any desired Ina-nner or made of any other suitable material.

Fig. 5 shows another form of lamp made according to my invention, the object of this form being to. afford a multiplicity of colors or light effects from 'a single lamp. The figure shows three tubes of glass or suitable translucent material I5, I6, II respectively, each furnished with individual electrodes I8, I9, 20 and 2|, 22, 23. In practice individual lead in wires can be led to each electrode as shown at 24, 25, 26, each being led through the walls of the glass tubes through properly insulated tubes preferably of glass, or I can provide a lead in wire common to all electrodes' as shown at 21 where the lead in wire is common to all electrodes and passes through the several light tubes. T'hese three tubes I5, I6 and I1 can be of .white glass or material or colored glass or material and the gases with which they are filled can be different or identical.

Inasmuch as the various noble gases such as argon, krypton, helium and neon each glow with a different characteristic color under the iniiuence of the electric current, it follows that according to the gas which is so electrically excited the color emitted from the lamp will differ.

'If the glassor other material from which the tubes are constructed is clear and white then the gases which are invisible when inert will not affect the colorof the gas which is excited and as each different pair of electrodes are connected with the source of electricity the gas excited will afford its own distinct color without any interference from the other gases which are adjacent.

However more than one set of electrodes may be connected simultaneously and a blended color may be secured'from a lamp, for instance, if a gas giving a blue light is excited and at the same time a gas giving a yellow light is excited, the resulting color of the light will be a blend of yellow and b lue, namely a green. Again instead of a simplegas being provided in each tube respectively, a blendA or mixture of 'gases -can be pumped into any or all of the tubes and by variations of this nature practically'any color or colors of the spectrum can be secured from a single lamp.

Similarly the glass or other translucent material from which the tubes are constructed can be varied in color to affect as desired the resulting color of the light passing through them.

In Fig. 6 the arrangement shows three gas chambers 28, 29 andV 30 arranged concentrically and provided with their individual electrodes 3l, 32 and 33 and 34, 35 and 36, the former group having their own individual lead in wires 3l, 38 and 39 and the latter or upper group having a common lead in wire 40.

Figs. 7 and 8 show one form of arrangement of a group of lamps of the nature before de"- scribed. Five lamps 4I, 42, 43, 44 and 45 are disposed around a. central reflecting chamber 46 (Fig. 8) and provided with a reflecting cowl 4l above which a transformer 48 can be attached. A pull chain 49 serves to actuate a switch. The reecting chamber 46 can be gas lled to serve as a source of light eitherin its entirety or it may be partially masked and partially open to direct its light in any desired direction. For instance, if the sides and top of such reflecting lamp chamber are masked or silvered it will serve as a top and lateral reflector, while if the bottom of said lamp chamber is left free to the passage of the light from the luminous gas within it. then a downward spot light will be secured. Similarly the reflecting lamp chamber can be of any' desired color to afford a different character of light from that afforded by the lamps surrounding it.

Figs. 9-15 show details of light exciting gas filled units designed to be combined for a multitude of desired effects. In these figures 5D represents a gas chamber of glass or other suitable translucent material as will be more clearly understood from reference to Fig. l2. This unit is segmental in nature and is designed to be arranged radially with other similar gas chambers as shown in Fig. 9. Central leads 50' connect the electrodes 5I arranged in each chamber and strip electrodes 52 are arranged at the outer periphery of the inside base plates of said chambers, said electrodes being suitably connected to the exciting current.

The arrangement is more clearly shown in Fig. 10 where the chambers 49 are provided with central electrodes 5I and base strip electrodes 52.

The object of this form of lamp is to provide a circular plane lighting lamp suitable for hanging or attaching to the ceiling and designed to throw a soft and diffused light downwards; to

assist this effect the upper planes of the gas chambers can be made of opal or green glass or silvered or provided with any other suitable reecting coating to prevent the upward escape of the light.

In Fig. 11 instead of unit construction the circular lighting plan'is shown as an integral chamber with container 50, upper electrode 5Ia and lower electrode 52.

In Fig. 14 the gas container is shown in two parts, an upper cover 50h and a base 53. The electrodes are shown as a conical central upper electrode 5Ib and a lower ring electrode 52D'. 'I'he container after being filled with electrodes and lead in wires is brought together with the base plate and the edges are cemented, welded,

or melted together so as to make an air-tight joint and the container after being exhausted of air and filled with gas is sealed hermetically.

acoaevs In Fig. 13 the container 50C is arranged over a base plate 53C which is joined to it by an hermetically sealed joint at its outer edge. A central electrode |c and a lower ring electrode 52 is xed in place and spacers or supports 54, preferably of glass, are fixed in place between the upper wall of the container and the base. The object of these supports is to prevent the deection of the walls of the container during the process of manufacture when the air is being exhausted or the gas is being introduced.

Fig. 1G shows a modification of my invention intended to provide a lamp suitable for projecting a beam of light in any desired direction. In the drawings an outer shell or cover 55 of any suitable material is provided with a peripheral rim 55 to hold a front cover or lens 59. The gas chamber 58 is mad-e of two concentric dishes of glass or other suitable material, preferably parabolic in contour, which are arranged to hold the exciting gas between them when their outerperipheral edges have been hermetically sealed at 59. Suitable electrodes 5B and Si .are connected by the lead in wires 62 and 63 to a transformer Ell which is, in turn, connected to the source of electrical supply. The back plate of the gas container can be silvered or provided with any suitable reflecting surface or cover to throw the light forward and the luminous gas lls the parabolic gas chamber and results in a beam of light being projected forward due io the contour of the gas chamber. When a lamp of such construction is used, for instance, as an automobile head light, it has the advantage of aording an intense beam of light which due to the absence of any internal lament is devoid of blinding glare as a person can gaze directly into the area of the light emitting unit without being blinded by its glare. Again it is a well known fact that the light emitted from luminous neon gas particularly has the power of penetrating mist or fog to a degree unequalled by any other illuminant and when this gas is' excited in a parabolic gas chamber such as 'herein illustrated, a source of light is provided which is particularly applicable to land, marina, or air signalling or illumination.

Figs. 17 and 18 show modifications of such a lamp especially applicable to lamps of large power and size. In these figures the parabolic gas chamber instead of being constructed of two integral glass dishes is built up of gas lled units similar in shape to that shown in Fig. 18. This gas container 65 is segmental in shape and when lled with gas and provided with electrodes and proper lead in connections is arranged radially as shown in Fig. 17-which is a part section of the front View of such a light projector. Here the gas filled units 55 are shown radially disposed in a projecting outer shell 55 which bears retaining lip 56 and cover glass or lens 5l, although in practice I may omit the cover glass altogether in lamps of any considerable size, as the glass gas containers themselves serve to project the light forward without the aid of a front lens.

Figs. 19-23 illustrate modifications of my invention designed more particularly for the manufacture 'o'f advertising letters, signs and the like and show methods of manufacture and sign products that have many important advantages. It is well known that luminous gas letters of the ordinary type are made from glass tubing which is heated and bent into any desired shape to form the letter or phrase desired. This method of manufacture is slow, expensive, and inadequate and the object of the methods and products illustrated in Figs. 19 to 23 is to eliminate these objections and provide a more artistic and use-s ful product. To effect this result I build my advertising letters or signs on a luminous gas illed plate either square in shape as shown in Fig. i9 or circular in shape as shown in Fig. 20, although it is obvious that a rectangular or other desired shape can be adopted. The process of manufacture is as followsz-A tray 65 (Fig. 19) is made of glass or other suitable translucent material and is either blown or pressed in a mould or fabricated by any other convenient method known to those skilled in the art. This tray is provided with raised internal ribs 66a and an'out side retaining rim 66h. These ribs do not entirely traverse the inside area of the tray being broken away alternately at the beginning and cnd as shown at 56C where the retaining rim has been broken away to show the method of construction more clearly. It will be evident from the drawings that a continuous path is thus provided by the depression between the ribs starting from one corner of the tray 66d to the far corner 66e and when the two electrodes itf and 65g are installed in place a cover plate of glass or like material 5i is placed over such tray and when softened by heat iswelded at its joints to the outside rim of the tray and to the upper flattened edges of the ribs which traverse the tray proper. A suitable aperture is left for the tray to be exhausted of air and filled with the desired gas for illumination and after this is done and the tray hermetically sealed the passage of the electric current from one electrode to the other is confined to the gas filled tubular path provided between the ribs described and the gas filled plate glows in the same way as a plate made from lengths of closely bent glass tubing. It is obvious that the glass tray or its cover can be of any desired area, depth, contour, color or finish and the upper or cover plate can be imprinted or decorated in any desired design without departing from the principle of my invention.

Fig. 20 shows a similar construction applied to a circular plate or tray in which the tray 66 is provided with a continuous spirally disposed and raised n or r'ib 66a and electrodes Sf and 65g.

Fig. 21 shows a decorated cover plate which has been cemented or welded over a circular plate such as I have described and serves to indicate the wide range of artistic effects-that can be obtained by this method of manufacture.

Figs. 22 and 23 illustrate practical methods of utilizing luminous plates such as I have described. GS shows a luminous plate of square design as applied to a base plate 68 which serves as a background and support for a letter sign. In this part ofthe figure the front cover plate has been omitted in order to reveal the construction more clearly. 6g shows the luminous plate covered with a front blank cover of suitable material while lll shows the addition of a front plate decorated with a letter I. This letter may be imprinted or superposed on the front plate in any suitable manner either in one color as shown in 'in or in a plurality of colors as shown in ll where the' cover plate i2 can be of one color, the letter can be of lanother color while a border around the letter 'i3 can be yet another color.` Thus by a selection of color in the excited gas in the luminous plate itself and the addition'of a color decorated front cover or second plate placedin front of such luminous plate cover practically any colored effect can be secured. Similarly the luminous cover or the plate placed in front of such luminous cover can be provided with a decorated border design as shown at I4 and decorated corners or other devices such as are shown at 'I5 can be provided. By this-method of manufacture it is obvious that each luminous signal can be filled with a different gas capable of giving a separate color when excited and these can be carried in stock by the manufacturer and will serve to form a unit or letter in any desired sign or device, all that is necessary being to slip in front of such a gas filled square the desired letter plate which may also be carried in stock. Again the sign can be changed at will by simply removing the front cover plate and the luminous square is protected at all times from the weather by the front plate. A number of other advantages and economies will occur to those familiar with the art.

Figs. 24-29 illustrate a modified method of construction whereby hollow letters of glass or other translucent material arepressed, blown, or moulded from sheets of the raw material. In Fig. 24 the plates *i5-'I6 are impressed with the letter F. TE one half of such letter substantially being fashioned from each plate so it appears tin half relief as shown at 'l1 in Fig. 25. The two plates are placed together and cemented or welded together at all joints so as to provide an hermetically sealed container for the gas which it is desired to use after the electrodes have been suitably disposed within it. The excess material surrounding the letter may be left as shown in Fig. 25 or removed as shown in Fig. 26, but in either event a hollow tubular letter is provided which when ntted with electrodes and lled with neon gas or the like can be used for advertising or other purposes.

Fig. 27 shows a letter of substantially square or block design and here again vari-colored effects may be secured by using colored glass of different hues or decorating the sides of the letters with suitable colored designs. In Fig. 27 the excess material left when the two parts of the letter are brought together has been removed, but in Fig. 28 the excess material has been left in part in the shape of a n or rib I8 and this fin or rib can be colored or decorated to give a contrasting effect from the body of the letter.

Fig. 29 is a side elevation of the letter shown in Fig. 28 showing the extending fin or rib 18.

Figs. 30 and 3l illustrate a new and simple means of manufacturing small luminous gas units in which a tube of glass or similar translucent material 19 is exhausted of air, filled with gas, provided with electrodes, and hermetically sealed in the usual way. The lettering of the sign is accomplished by the use of attachable letters made of any suitable material and of any desired color or colors. These letters are placed in the desired position and cemented or welded into position outside the gas lled tube till they spell out the word or phrase desired as shown in Fig. 3l. An outside casing 8| can be placed around the luminous tube for protective purposes and a transformer 82 can be attached to the tube with a leadl in wire 83 which serves to connect the unit to the source of electric supply. It is obvious that the tube can-be provided with a front plate bearing the letters in relief or imprinted or attached to same in any suitablel ma.'n\ ner without departing from the principle of my invention and again any suitable reflecting surface can be placed at the rear of said tube to enhance the brilliance of the lighted tube.

Figs. 32, 33 and-34 show details of the internal construction ofv gas filled letters made according to my invention and illustrate the use of auxiliary deecting internal partitions to control the course of the illuminated gas from electrode to electrode. In the illustrations the letters 84 have internal partitions disposed according to the needs of each respective letter.

In Fig. 32 the electrodes 86 excite the gas which follows the path as indicated by the arrows in the illustration. It is obvious that without these partitions 85 the current would seek the shortest path from electrode to electrode without illuminating the whole letter, but by the use of these partitions the current is compelled to traverse the full length of the letter thus illuminating the entire area.

In Fig. 33 no internal partitions are employed,

the current being free to follow its own path from electrode to electrode and as the path around the top half of the letter and the bottom half of the letter is identical in length and resistance, an equal illumination is secured.

In Fig. 34 the electric current can follow either of several paths from one electrode to another, but all of these paths present equal resistance and in no event can any portion of the letter remain unilluminated.

Figs. 35, 36, 37, 38, 39 and 40 relate to improvements in electrodes for use in luminous gas lled lamps. In Fig. 35 the electrode consists of a tube 81 preferably of glass provided with a lead in connection 88 which is in intimate electrical contact with a metallic or conducting lining 89 in the tube 81. This conducting lining may be an electrically deposited metallic coating or a sheet or tube of metallic foil. A hollow conducting electrode is thus provided through which the excited gas can circulate.

Figs. 37 and 38 show an electrode made from a spirally coiled wire of suitable material, the

coil 9U as shown in detail in Fig. 38 i's inserted in the tube 81a as shown in Fig. 3'?, but is shielded from actual contact with the gas to lbe excited by an inner lining 9i, preferably of glass. The electrode chamber thus formed can either be lled with'air or preferably the air is exhausted from said chamber thro-ugh the air vent which is subsequently sealed in the usual manner. The object of enclosing the actual electrode surface away from contact with the gas to be illuminated is as follows. It is a well known fact that the luminous qualities of lamps of this character decrease sharply after a few` months of use and this I nd is principally due to the pollution of the gas itself from particles of the electrode metal which are thrown off due to the influence of the high poten-tial current employed. By totally enclosing the electrode as shown, the energizing current is of sufficient intensity to act through the thin glass wall of the enclosing secondary tube and thus illuminate the gas with which the lamp is lled, but any particles thrown olf or torn off by the pulsations of the current are prevented from having access to the gas itself and pollution and deterioration of the latter is thus prevented and the life of the lamp is greatly prolonged and the purity of its color maintained.

Figs, 36 and 39 show a form of electrode in which a suitable'metallic or conducting powder is employed with a view of alfording the maximum emitting surface in the most compact form.

In Fig. 36 the outer tube 3lb is preferably provided with an inner metallic coating 93 and a front sealed wall 94. After the tube has been filled with the suitable powder electrode 95 it is exhausted of air through vent 92 and hermetically sealed. 96 shows a metallic electrode lead in designed to establish perfect contact with the metallic powder which in turn is in intimate contact with the metallic skin or cover 93 lying in close contact with the glass container 81 through which the energy passes to the gas in the lamp chamber.

In Fig. 39 the construction is similar with the exception that the conducting powder electrode is disposedin the container 81c and around an internal tube 91 which permits the gas charge of the lamp to have access to the powdered electrode. through the glass wall 98 inside the electrode as well as through the outer glass wall of the container 81C.-

Fig. 40 shows a means of modifying or controlling the color emitted by the gas with which the lamp may be lled. The con-tainer 81a is lled with suitable electrodes 96EL exhausted of air and filled with neon `or other similar gas. Before the container is sealed however a quantity of powder 91*1 of impalpable neness is introduced into the lamp which is then sealed in the usual way. Under the influence of the electric current the impalpable particles of powder become diffused throughout the gas with which the lamp is filled and modify the light emitted by the excited gas according to the na-ture of the The powder selected can be of any desired constitution but is preferably of a no-noxidizable inert nature which involves no chemical reaction'with the gas in the lamp although for special purposes I may elect -to use a powder having a definite reaction with the gas in the lamp where modifications of intensity, diffusion or actinic values are desired.

Figs. 41 and 42 show details of an improved transformer or booster designed to operate on an electric circuit of comparatively low. voltage and transform or step up said voltage to the high potential commonly used in luminous gas lamps of this nature. This transformer shown is designed to operate by plugging into the usual 110 volt house current and combines a plug for that purpose, transformer primary and secondary coils, alsafety switch of novel design, and a socket to receive the lamp lled with neon gas or the like.

In Fig. 42 a shell or housing 99 holds the primary and secondary coils and is provided at its lower extremity with the screw socket contact piece 99a designed to screw into the house socket. At the upper extremity is a' socket |00 with bayonet joint |0| designed to receive the base of the lamp lled with neon or like gas (|04, Fig. 41). A rotatable pointer |02 moves over the gauge 43 and indicates the intensity of the alteration which is being excited by the transformer. Fig. 4l shows details of internal construction of my improved transforming socket and plug in which the housing 99 bears the coils |05 and |06 which are attached to the leads |01 and |08. At the top vof these coils are arranged the double contact pieces |09, H0, which are so coupled to the transformer coils that the passage of the current is interrupted by the gap which exists between the two poles of each spring contact pair until the lamp |04 is screwed tightly in place.

Theobject of this construction is to avoid dangerous sparking between terminals carrying high glass.

potential current for it is obvious if the 110 v. circuit which enters through the base socket 99* were permitted free access through the transformer coils to the terminals in the upper socket |00 vthe poles in the latter bearing a current of many thousands of volts would spark and provide a source of danger from iire and unpleasant shock to any person accidentally touching them evenA while the low amperage would obviate the possibility of' any serious injury. The operation of my improved socket as shown prevents any possibility of this as the action of the spring contact pieces in the upper socket precludes the possibility of any current between them until the lamp |04 is securely in place and contact of both poles of the lamp has been thoroughly established. In practice the socket is insulated from the source of current (such as the house circuit) and dead until the lamp |04 is screwed into position. As

'the base of lamp |04 descends into the screw socket (or bayonet joint as shown in Fig. 42)

it rst establishes its own contacts with the lines from the transformer coils but as the latter are not yet energized from the house circuit no possibility of sparking exists. The last movement downwards of the lamp |04 in the socket |00 however depresses the spring contacts ||0, ||0 into electrical contact which permits the house current to enter the coils and energize them but as the poles of the lamp |04 are already firmly in contact with the. highpotential terminals of the lcoil no sparking or unpleasant electric effects are possible. The use of such a compact safety transformer plug permits a much wider' use of luminous gas lamps than before as no main transformer is needed on the circuit and a lamp lled with neon gas or the like can be easily and safety attached into any ordinary 110 v. socket provided this transforming plug is interposed between it and the lamp.

Fig. 43 shows an adaptation of some of the constructive details I have described to a notice or bulletin board suitable for advertising or other purposes. A vertical hollow gas filled tray is furnished with internal ribs ||2 and covered with a cover 3 preferably of frosted, ground or opal The tray itself is gas filled, provided with electrodes, ||4 and on passage of the electric current along the depressions provided by the internal ribs, glows with lights as I have already described in relation to Figs. 19 and 22. This tray or hollow plate lamp is mounted on a suitable support ||5 with which one or more transformers ||6 can be incorporated. When employed as a notice or bulletin board any desired message may be printed or written on the covering glass in front of the lamp and an actual piece of merchandise such as the cigar i1 can be temporarily fastened on the said cover. desired to change the message on the board the merchandiseis removed and the writing wiped oif or otherwise obliterated and a fresh message substituted. I

Figs. 44 and 45 illustrate a method of manufacturing hermeticaily sealed glass containers from glass moulded forms.

Fig. 44 shows in section upper and lower glass tray like blanks which it is desired to seal at their overlapping edges.

The lower tray I8, Fig. 45, is covered with the top tray |9 both made of glass or other suitable material. A cover of suitable material |2| is then placed above it and held rmly in place by any suitable means. Compressed air is introduced between the upper and lower plate'through the When it is Cil glass, air pipe |22 which enters the base of the lower glass plate at i23 being introduced by heating and perforating the lower plate in a manner well understood by those skilled in the glass blowers art. Heat is applied to the lower mould by means of a gas main |24 from which the flames or heated air |25 issue and play over the surface of the lower mould. The glass containers inside the mould become softened with the heat till the side walls which overlap are sufficiently melted to weld together under the pressure of the air which is forced through the air pipe |22. After this has been accomplished the mould and contents is allowed to cool till the welded glass container can be removed from the air inside-is exhausted and any desired gas introduced through the air pipe |22 which is then sealed and cut off close to the surface of the lower part of the container. In the illustration shown by Figs. 44 and 45 the glass moulded blanks have already been provided with the side walls by a previous moulding operation, but it is obvious that this part of the process of manufacture can be combined with the sealing operation and the sheets of glass from which the upper and lower part of the container are to be formed can be introduced into a mould substantially as shown in Fig. 45, and after heating the side walls of the containers can be first shaped by pressure and the sealing operation can follow as before described.

Figs. 46 and 47 illustrate a modication of my invention as applied to a conventional sign for barbers. A central supporting frame |26 bears one or more spirally wound glass tubes |27, |28 and |29, each tube being filled with a gas which upon being electrically excited will glow with red, white and blue light respectively. IA small transformer can be housed in the lower part of the frame |26 from which the lead |30 emerges to connect with the source of electric supply.

Fig. 47 shows a modification in which a g'ass tube I3 |y preferably of square section, is imprinted or covered with plates of red, White and blue color as shown and mounted in a frame |32, the base of which bears a transformer E33. The glass tube vis fitted with electrodes and filled with a luminous gas, thus constituting a lamp, and the decorated and colored panels on the sides identify it as a barbers sign.

Figs. 48, 49 and 50 show the adaptation of a luminous gas lamp as hereinbefore described, to a dummy head for barbers display indicating an appeal for feminine patronage.

In Fig. 48 a hollow blown or moulded head |34 is gas filled, and fitted with suitable electrodes and supported by a base |35 covered by a projecting glass cover |36. -When the current is turned on the interior of the head glows with light affording a brilliant advertising sign.

Fig. 49 shows a base |35 supporting a hollow gas filled lamp |36 on one or more faces of which .l

is imprinted a female head to serve the purposes before described, while Fig. 50 shows still another modication in which a double faced moulded head, preferably of glass, and suitably decorated, is gas filled and provided with electrodes to serve as a barbers sign.

Fig. 51 is a modification of the multi-color lamp described in Figs. 5 and 6, but is more particularly designed for projection purposes. In this form a plurality of lens like chambers |31, |38 and |39 are placed one in front of the other and each provided with a pair of electrodes IMI-'MD-MO. of air, gas lled with the desired gas, and provided with suitable lead in wires in the usual manner.

If preferred the reai` gas chamber can be silvered on its back for reecting purposes or the series of chambers can be mounted in a suitable frame bearing a reflector at its back.

It will be obvious that by selectively exciting the different color gases with which the several chambers are filled, a variety of color beams can be directed forward from such a projector.

I claim:

An electric gaseous discharge device comprising a sealed envelope containing. a gaseous atmosphere, electrodes sealed within said envelope and means to direct a gaseous discharge into a plurality of paths along the surface of said envelope, said means comprising a concentric inner member having ridges in contact with said surface.

ARTHUR S. FORD. v

These chambers are exhausted 

